Air con compressor not working

**Fourbears** · 18-05-2009,08:43 PM

My compressor won't turn on despite the Climatronic being on auto. The clutch isn't engaging so apart from checking power to the yellow/green wire, what else? I know its fully gassed and there are no leaks. Is there a relay somewhere to check as the fuse is ok? Where would I find the pressure sensor and is it easy to replace?

**martin1810** · 18-05-2009,08:56 PM

The pressure sensor should be behind the right hand head light. The magnetic clutch on the pump may have failed.

**Fourbears** · 18-05-2009,09:05 PM

Presumably the clutch can be changed?

**martin1810** · 18-05-2009,09:13 PM

Yes the clutch can be changed. I'd go for the pressure sensor first. Maybe get a scan incase it reports an open circuit somewhere.

**Fourbears** · 18-05-2009,09:17 PM

Any idea what the part number is?

**easylifeauto** · 19-05-2009,06:19 PM

are u sure its gassed fully?i thought mine was,had it re checked/flushed/regassed and now working fine?just a thought before takin things apart?

**snapdragon** · 19-05-2009,07:23 PM

On mine, it was not engaging, so I took it to an aircon place who regassed it and after a couple of days it stopped working again. In the meantime I did a fault code read with vagcom. I had the fault code for the pressure switch behind the bumper bar. I replaced this to no avail (same fault and code) and went back.

They apologised and gave me a refund for the initial regass and said it had leaked out of a pipe and they ordered the pipe and regassed. It was fine after that, but quite dear as the pipe was expensive and buried under other stuff

**Fourbears** · 19-05-2009,08:21 PM

Ok, its fully gassed up and there are no leaks. There is no power to the compressor and I've traced the wire back to where it enters the harness underneath the power steering reservoir where there is still no power. I still can't see the pressure switch so where can I find that? Haynes isn't helpful for that! I assume that I have to have the system drained to replace the switch? Is there anything else I need to check?

**snapdragon** · 19-05-2009,09:07 PM

If there is insufficient pressure (or it thinks so because of duff sensor) then it will not even try to engage the clutch. This may be your case.

The sensor on mine was behind the bumper under the driver's headlight and even with the bumper off, it was hard to get off as it is nestled with metalwork around it (on mine anyway).

You unplug a 4 pin connector off it and then unscrew it with a spanner. The connection comes off is self-sealing and looks just like a tyre valve.

The location may be different depending on year and engine on yours by a few inches judging by other descriptions I read at the time.